Brain oscillations track the formation of episodic memories in the real world

Neuroimage. 2016 Dec;143:256-266. doi: 10.1016/j.neuroimage.2016.09.021. Epub 2016 Sep 10.

Abstract

Despite the well-known influence of environmental context on episodic memory, little has been done to increase contextual richness within the lab. This leaves a blind spot lingering over the neuronal correlates of episodic memory formation in day-to-day life. To address this, we presented participants with a series of words to memorise along a pre-designated route across campus while a mobile EEG system acquired ongoing neural activity. Replicating lab-based subsequent memory effects (SMEs), we identified significant low to mid frequency power decreases (<30Hz), including beta power decreases over the left inferior frontal gyrus. When investigating the oscillatory correlates of temporal and spatial context binding, we found that items strongly bound to spatial context exhibited significantly greater theta power decreases than items strongly bound to temporal context. These findings expand upon lab-based studies by demonstrating the influence of real world contextual factors that underpin memory formation.

Keywords: Context; Episodic memory; Mobile electroencephalography; Oscillations.

MeSH terms

  • Adolescent
  • Adult
  • Beta Rhythm / physiology*
  • Electroencephalography / methods*
  • Female
  • Humans
  • Male
  • Memory, Episodic*
  • Mental Recall / physiology*
  • Spatial Memory / physiology*
  • Theta Rhythm / physiology*
  • Young Adult